alright guys need an opinion. did a compression check on the cylinders that i could get the tester on. (coulden't get them on 5 and 7) stupid ac. anyways... here is what i found 1 - 152 2 - 127 3 - 127 4 - 127 5 - xxx 6 - 105 7- xxx 8 - 127 now... I think the 105 maybe a bad number but got it 2 times by tightening but It was a loaned tool (and i didnt want to tear the old O ring on it and when putting the spark plug in i hit a goofy spot where it took a lot of force to get it past (so I coulda had blow by.) but it could also be a bad cylinder... anyways.. now the questionable one is the 152. I got this reading 3 times. (or really close) can someone shead some light on that cylinder? this to my knowledge is an un opened buick 350 with 145k miles on it. also can some one show me a link to what diffrent pics of burn quality of spark plugs? mine seem kinda white. ( i dont have HEI not that that makes much diffrence) I also had 2 that were wet oily.. (one was my #8 (loosened it self up and valve cover leaks. and the other was #3. think a bad plug) these plugs had about 8k miles on them. hmm.. wonder If i were running on only 6 cylinders. for awhile. Nate
i would think the fouled plugs are probably just from leaky valve seals...they'll do that after 150k. did you squirt some oil in any of the cylinders to see if compression improved a signifigant amount?
no i didnt check. though what should a recent rebuild number be though for a compression check.. Nate
I'm assuming these numbers are for your 1970 350 4V. The main thing you are looking for is consistency. I hate to say this, but those numbers are not great. That thing should have 150-160 lbs per cylinder. I think you need to try the test again. Are you cranking the engine over more than once? Don't stop at the first gage movement, stop after it compresses three or four times. If the numbers it posts really suck, spray some oil or WD 40 into the cylinder. If the number increases, its in the rings. If it stays the same, the heads need done. I've heard it said that having the throttle plates open helps, but I never do it that way. Also, make sure your battery and/or starter is up to snuff. If it starts turning slower as you go down the cylinders, your numbers will fall off. Good luck. I hope test number two is good.
I'd think they were fairly consistant. nearly all about 130psi. the 150 threw me. I'll try again when I change the brakes on it. and i can get it in the garage. a screwdriver put into the 2ndarys I cranked for about 3 seconds. about 3 rotations... its been sitting for awhile and the battery did go down as it went further along. the power while accelerating it seems low though so it could be just lousy but I thought it was a flat cam. it is also the low compression ratio though, it orginally was a 2bbl. although it shoulden't make much diffrence with multiple rotations i'd think. should this have been done this with the engine warmed some or cold? I did this on an engine that has been sitting for about a month w/o firing it up since putting it away. the plugs have a light white look to them but not much blackened carbon. it does consume oil (about .75 of a qt every 600 miles on highway 75 mph and highway gears. Nate
